Which test and why
All physicians will agree that a patient’s diagnosis is derived primarily from the initial consultation and examination. However, with the increased documentation requirements by third party payors the medical-legal arena has changed. Objective evidence of injury has taken the place of the “expert physician opinion” which is based solely on the subjective findings of conventional orthopedic, neurologic, physical and chiropractic examinations. Many new procedures are available for the objective documentation of soft tissue injuries.
The attorney needs to keep abreast of these hi-tech procedures to assure that the health care team managing their client’s care is also considering the documentation requirements of the case. The soft tissue health care team which is usually composed of neurologist, orthopedist, chiropractor, physiatrist, psychologist, radiologist and general medical specialist should work in concert to assure that all necessary diagnostic and documentation requirements are satisfied.
The following are some of the tests which can benefit the patient’s care as well as document the extent of injury:
Magnetic Resonance Imaging (MRI)
MRI scanning has earned it’s place in the soft tissue injury arena because of it’s sensitivity in identifying early degenerative changes which can occur in the disc post-traumatically. It’s applications go far beyond just locating areas of disc disease and most attorneys appreciate this increased sensitivity. No other imaging modality has the ability to look at the neural structures as well as MRI imaging. MRI imaging can obtain both anatomical and physiological data. Like CT scanning it has the benefit of identifying fractures and disc herniations but an increased benefit is it’s fine density resolution of the neural elements which are often damaged in trauma cases. Using different sequences, some injuries can be identified as acute, subacute or chronic thereby helping to establish causation.
Also known as fluorovideo Motion Analysis (FMA), Dynamic Motion X-ray (DMX) and Cineradiography, it has the ability of recording joint and spinal motion x-rays on video tape. This is useful in evaluating kinetic and kinematic abnormalities. It is extremely sensitive for the evaluation of ligamentous integrity. This test is most appropriate for patients that have sustained acceleration/deceleration trauma when there is the possibility that the anterior and posterior supportive structures of the spine have been put under excessive stresses. It is the single most valuable test in identifying abnormalities of joint coupling which is the underlying cause of spine pain from biomechanical origin. Recorded on video it is a powerful forensic tool for demonstrating to a lay person the results of trauma.
3-D Computed Axial Tomography
3-D CT scanning and reformatting capabilities have given the radiologist greater ability to evaluate structures which were previously inaccessible. With this procedure the radiologist can visualize the spine and soft tissues from nearly any angle and plane. This can be particularly helpful in diagnosing stenotic foraminal conditions secondary to bony or soft tissue involvement.
Electromyography (EMG)/Nerve Conduction Testing (NCV)
EMG and NCT examinations are the examination of choice for people who have motor or sensory problems involving the spine and extremities. It has the capability to differentiate between nerve, muscle and motor neuron junction diseases. For radiculopathies, myelopathies and plexopathies involving the motor system it is particularly sensitive. The one short comming is the inability to document sensory complaints which occcur proximal to the plexus. Therefore, the majority of patients who have pure sensory complaints arising from the spinal cord or spinal nerve root may go undetected. To fully assess both motor and sensory pathways EMG, NCT and SSEP should be performed.
Musculoskeletal Ultrasound (MSK)
Musculoskeletal Ultrasound is a technology that has been around for quite a while but has recently become a preferable diagnostic tool for several reasons. First, the technology has advanced such that the images are far superior to ultrasound images from just a few years ago. Second, the imaging technique does not involve ionizing radiation. Third, the cost of the equipment and thus the cost of the procedure is much less than MRI and CT. Fourth, ultrasound imaging is real time and functional. This means that the structures examined can be seen in both static and dynamic states thereby assessing functional losses. Fifth, the imaging can be done in the doctors office at the time of the routine examination. Sixth, when used during injections,biopsies and aspirations, the accuracy of needle placement is confirmed thereby preventing damage to other tissues and assuring that procedures are more effective.
MSK Ultrasound imaging is particularly helpful in assessing soft tissue structures due to it’s ability to distingush characteristics of different tissue densities. In other words, fat, muscle, tendons, ligaments, fascia, nerves and bones can be distinguished. Also, fluids can be distinguished (blood, cysts, synovial fluid, etc). This makes connective tissue lesions more easily diagnosed resulting in better defined and more quickly implemented treatment protocols. MSK Ultrasound is presently being used for shoulder, elbow, knee, wrist, finger,, hip, knee and ankle assessment. It is also used for a variety of guided injections into joints, muscules, tendons. ligaments, nerves and plexus.
Bi-Directional Doppler, Photo and Pneumo Plethysmography
Doppler and plethysmographic equipment is used to assess blood flow, direction and velocity. Vascular studies such as doppler and plethysmography further define the patient’s compliaints of pain. Often times a patient involved in a trauma may develop extremity complaints of a vascular origin. Conditions such as Thoracic Outlet Syndrome (TOS) can occur as a result of cervical muscle spasm or adhesions and are best diagnosed by plethsmographic examinations. Reflex Sympathetic Dystrophy also has vascular components which may be secondary to trauma and identified using photo-plethysmograhic equipment. Patient complaints of headaches must be differentiated from dangerous vascular disease and therefore cerebrovascular screening exams can assist in the diagnosis of post traumatic headache by eliminating carotid atery disease.
Somatosensory Evoked Potentials (SEP)
SEP’s are an exciting electroneurodiagnostic procedures which has lately become less popular despite improvements in wave form acquisition. It has the unique ability to measure sensory abnormalities which conventional electromyography (EMG) and nerve conduction velocity (NCV) can not usually detect. When used properly, the SEP can localize and quantify the degree of sensory impairment and assist the doctor prognosticate outcome. The testing involves the use of several hundred electical stimulations which are recorded along the nerve sensory pathway to the brain. At the level of the brain, the responses are smaller than the background brain activity. Through the use of advanced frequency filtering and fast fourier transform averaging of the time locked stimulations, wave forms can be isolated. Once isolated, they are compared to normative data and the uninvolved side for determination of conduction abnormalities. Stimulation can be to specific nerve trunks or even dermatomes for identification of specific levels of neurologic involvement.
Current Potential Threshold (CPT)
CPT testing, like the SEP’s, have the ability to document involvement of the sensory nervous system. When used in conjunction with SEP’s a assessment as to which nerve sub-populations are involved can be determined. This type of testing has not been well accepted despite its potential utility.
Electronic Infra-red Thermography
Thermography has the unique ability of measuring the physiologic status of both the musculoskeletal and neurological systems. It is a measure of body heat which is directly related to the vascular perfusion of the skin. Since vascular perfusion is neurologically controlled by the autonomic nervous system this is essentially a neurovascular test. It’s use has clearly been accepted in patients with Complex Regional Pain Syndrome (CRPS) previously known as Reflex Sympathetic Dystrophy (RSD), Sudeck’s Atrophy or Sympathetic Maintained Syndrome. These conditions can be incredibly debilitating and not very responsive to treatment resulting in very large functional impairments. When interpreted by a board certified thermographer the test can greatly assist the doctor and attorney by graphically demonstrating the abnormalities present. Juries are particularly impressed by the color representation of soft tissue damage. Unfortunately, the technology had lost some of its glory due controversial claims in the 80’s and 90’s. Recently, it has become of greater accptance again, particularly in breast cancer screening, where the literature support is strong for its sensitivity (not so much for its specificity). I beleive when properly utilized and used prudently it is a test that has both clinical and forensic benefit.
Topographic Brain Mapping
Brain mapping offers exciting possibilities in the documentation of head trauma cases. It represents a computer enhancement of raw electroencephalographic (EEG) data. It is displayed topographically with colors representing different frequencies and amplitudes of spontaneous brain electrical discharge. Like Thermograph, its glory days were the 80’s and 90’s and has lost ground due to political rather than clinical issues.
Isokinetic Muscle Testing
Isokinetic muscle testing equipment has the ability of quantifying muscle strength deficits which are produced with extended exertion. Most quality equipment will produce torque curves which can enhance evaluation and fatigue assessment. Cybex in particular has established normative data which make objective impressions to be generated from the raw data.
The computerized digitization of plain film and fluoroscopic images allows for greater sensitivity in the interpretation of radiographic studies. The computers have the capacity to draw lines of mensuration much more accurately than a technician or even a physician. The computer can instantaneously locate areas of altered biomechanical stress or structural abnormality. Areas of trauma and vulnerability to trauma are identified and quantitatively presented. Conditions such as canal stenosis, spondylolisthesis, instability, laxity, altered weight bearing, kyphotic subluxation can easily be identified and graphically presented.
Electronic Digital Inclinometry
Range of motion studies of the spine require the use of an inclinometer to differentiate localized spinal movements from accessory spinal movements. The old method of using a goniometer could not eliminate movement from adjacent parts of the spine and therefore were often times found to be inaccurate. The American Medical Association’s “Guide to the Evaluation of Permanent Impairment” require the use of an inclinometer in its assessment of impairment using the range of motion model. With this in mind it is prudent to utilize electronic digital inclinometer to asure accuracy and reproducibility of the range of motion examination